Compact design in receiver and misalignment tolerance are two basic considerations for practical applications of wireless power transfer (WPT) in unmanned aerial vehicles (UAVs). To balance these two requirements, a novel magnetic design with the composite interval-acted parallel- & vertical-flux throw, orthogonal two-dimensional flux pick-up, and power-flow summed output is proposed in this letter. The resulting magnetic structure includes a target-shaped transmitter and two quadrature receivers, and the transmitter consists of four annular-type coils which are magnetized in a bipolar mode, making it possible to form a magnetic field with a parallel- and vertical-flux complementary distribution. Moreover, by integrating two orthogonal receiving coils into one receiver, a stable summed output current can supply the UAV onboard load with only a small size receiver. A UAV WPT prototype is established based on the proposal. The results show that the prototype can deliver 325 W with a system efficiency of 86%, and especially the variation of the output current is within ±0.76 A for different landing positions and directions. The overall system efficiency is from 87.3% down to 83.1%.

This letter proposes a novel capacitive power transfer system for the unmanned aerial vehicles (UAVs) with lightweight in receivers and robust misalignment tolerance characteristics. The design and analysis of a reconfigurable capacitive coupler are presented at first. The transmitter adopts four rectangular copper plates, which can be reconfigured according to the landing positions and directions. The receiver includes two hollow cylindrical copper-foil sleeves wrapped at the bottom of UAV landing gears, thereby leading to the adaption of the UAV's structure and the tolerance to lateral-, longitudinal-, and angular misalignment. Then, simulation and prototype experiments are carried out to verify the proposal. The results show that the prototype has low leakage electric flux at the UAV fuselage and can deliver 212.1 W with a dc-to-dc efficiency of 82.5%. Especially the proposal allows UAV to be powered within ±0.76 A of output current variation for different landing positions and directions, and the system dc-to-dc efficiency variation is within ±1%.

This letter presents a novel unipolar and bipolar magnetic channel multiplexed wireless power and data simultaneous transmission system for autonomous underwater vehicle (AUV) applications, wherein bipolar coils are utilized to transfer power with the horizontal flux, and the unipolar coil is utilized to transfer data with the vertical flux. The receiver, which has only 741 g and a compact structure, can realize decoupling for the channels by utilizing the orthogonal coils to receive the perpendicular flux. The integrated design of bipolar orthogonal power channel and unipolar parallel data channel effectively reduces crosstalk and realizes decoupling. To further improve the reliability of data transmission, the wave traps are added to suppress power crosstalk in data channel. The proposed structure is verified by experiments, the output power can reach 936 W with a DC-DC efficiency of 94.12%, and can also realize full-duplex communication.

Autonomous underwater vehicle (AUV) is a key mobile node in the ocean observation network. However, the limited endurance capacity and limited cruising range have become the bottlenecks in the wide application of the AUVs. In order to extend cruising range, this article develops a uniform power inductive power transfer (IPT) system for AUVs. A novel magnetic coupler with a low output fluctuation, low weight of receiver and a low space occupation of the AUV is proposed in this article. The proposed magnetic structure employing a quadruple-coil transmitter and a crossed dipole receiver utilizes uniform horizontal magnetic flux to establish stable coupling against rotational and axial misalignment. An IPT circuit topology is designed and analyzed in detail, meanwhile, the phase difference of the excitation currents is optimized to achieve the power and efficiency stability versus misalignments. The proposal is analyzed, established, and tested in this article. The magnetic receiver weighs only 414 g. The results show that the prototype can deliver 964.7 W with a dc–dc efficiency of 90.9%. In the process of rolling dislocation from –20° to 20° and axial dislocation from –30 mm to 30 mm, the maximum fluctuation of output power is 12.1% and 20.2%, respectively.

Wireless charging systems in unmanned aerial vehicles (UAVs) should be compact, lightweight, and misalignment-tolerant. Equipment required for better performance, such as the receiver, cannot be placed outside the drone body, which would cause additional flight power resistance. To satisfy more demanding requirements, a novel squirrel-cage receiver coil embedded in the landing gear of a UAV is proposed. It avoids flight resistance while achieving a lightweight, simplified structure for the transmitter and receiver coils. In the experiments, a main circular transmitter coil with a 440 mm outer diameter was used. The dc–dc efficiency was 78%–80% and the output current was 2.47 ± 0.13 A in a 0–320 mm diameter area. The efficiency was >74% and current was 2.05 ± 0.15 A in a 320–440 mm diameter area. The results show that the squirrel-cage receiver coils combined with a main and a small circular transmitting coil has good misalignment tolerance performance.

This paper proposes an optimal design for a salient pole wound field synchronous machine (WFSM) with a single flux barrier to improve torque performance and obtain a wide operating range, simultaneously. The proposed WFSM motor can effectively decrease q-axis inductance to improve the saliency ratio (X _d /X _q ) and increase the reluctance torque. To maximize the saliency ratio and improve the torque characteristics, the single flux barrier is optimized, considering the magnetic saturation that uses Kriging method based on Latin hypercube sampling and a genetic algorithm. The 2-D finite element analysis results by the aid of JMAG-Designer shows that the saliency ratio X _d /X _q , the reluctance torque, and the total torque of the optimal model are increased by 9.27%, 20.45%, and 6.17%, respectively, compared with those of the basic model. Finally, the performance of the optimal motor is verified through an experimental test, which indicates good agreement with the simulation results.